delta17-20-cyano-11-hydroxypregnenes



Patented Oct. 20, 1953 UNITED 12,656,368 A -20=CYANO II- HYDROXYPREGNENES Robert :P. Graber, Westfield, and 'Norman L.

Weniller, Linden, N.

J assignors 'to Merck &

'Co.,'i"Inc., 'Ralhway, N. J.', a corporation of'New Jersey No vl rawing. Original application December 2,

1950, .SerialNo.'198,916. Divided and this applic'ation January 8,

- 9 Claims.

This invention .is concerned generally :with novel-steroid compounds and with processes -for :preparing them. More :particular1y,:it relatesrto -a.nove1 processfor the .preparationof A a-3,20- -diketo-l1,172letrihydroxypregnene and 21-ac- :ylated derivatives thereof-"starting with"A -3,11- diketo -20-'cyano-2 l-hydroxy-pregnene f or -'2-1-acyl derivatives thereof, and to the intermediate com- :pounds utilized in this 'novel'procedure.

This :applicationis a division of .ourscopending application Serial -.-No. 198916, filed :December 12, 1950.

The hydroxyl groupings attached to the 11 and 17-carbon atoms in the intermediate and final compounds, prepared according to our novel process, possess the same stereochemical configurations as that present in many of the naturallyoccurring adrenal hormones. The configuration of the ll-hydroxyl substituent in such: naturallyoccurring steroids (and in the compounds-prepared in accordance with our-procedure) has been found to correspond tothat ofthe two angular methyl groupings and the side chain of the The ll-hydroxyl radical in" steroid molecule. such compounds is conventionally designated :-5,. and is written above the plane of the ring system; i. e.,-.the OH radical is connected to the ll-carbon atom by means of a full line in=-thechemical formulae of these compounds. The configuration of the l'l-hydroxyl substituent in these compoundshas been found to be transposedto-that of the two angular methyl groups and ito the side chain of the steroid molecule. The 17-hyiiroxyl radical is conventionally designated wandiswritten below the plane of the rin-g system; i. e., the O'H radical is connected to -th-e '17-carbon atom by means of .a dotted line. rhus, our novel process is especially valuable in the synthesis of the natural adrenal hormone, A -3,20-diketm 11(5) ,17(a.) ,21 trihydroxy pregnene (otherwise known as Kendall's Compound F) which may be chemically represented as follows:

Although A -3,1'1,20-triketo-17 (on) ,-hydroxy-21e dihydroxy-pregnene, commonly known ,fiaIsQCOT- tisone, and its.l-21-a*cy;l derivatives have been prepared heretoioredoy chemical synthesis, the preparation of Compound F, or of other cortical steroids hydroxylated at position 11, utilizing, as starting material, cortisone, or other ll-keto- 10,13 dimethyl cyclopentanopolyhydrophenanthrene compounds .obtainedas intermediates in the: synthesis of cortisone, such as n -3,11:-diketo- .'20-cyano 21-hydroxy=pregnene, "has :preuiousl-y encountered an apparently insurmountable ob- 5 stacle by'virtue of ithetfollowing chemical tracts: (1) -Thezpolyfunctional character of this=c1assof steroidszand the fact that suchsteroids ordinarily iBOSSBSS additional keto substituents in the -3 .and/or 20-.positions of the molecule; "(2) The extremely lowreactivity (ascribed to Lsteric hindrance') of the l'l-keto substituent; :and (3) Ethe -known:susceptibili-ty of. the. 5-hydroxyl group at position 11 to oxidation and elimination reactions, together with the seemingly anomalous inertness 15 of the 11(5) -hydroxyl to aoylating agents.

Thus, when'an i11keto-10,13-dimethyl-cyclopentanopolyhydrophenanthrene compound containing additional keto substituents in the 3 and/or -positions is reduced utilizing conven- .2()-tiona1 methods of hydrogenation or chemical reduotion, itfhas been found that reduction of the keto radicals in the 3 and/or 20-positions takes ,pla'ce preferentially to the reduction of the 11- ketone. Only by employing relatively drastic re- Bdfiduction conditions, is it possible to reduce the ll-keto substituent andrunder such drastic conditions of reduction, ;the 3 and/or 20-keto groupings are likewiw reduced. The compounds thus obtained, in attempted syntheses of cortical steroids are 10,13-dimethyl-cyclopentanopolyhydrophenanthrenes containing an 11(5) -'hydroxy radical and additional hydroxy radicals in the 3 and/or 20-positions of the molecule. Attempts to "convertsthese 3 and/or ,r2'0 -hydroxy radicals by reaction with oxidizing agents to the correspondin -.ketosubstitnents, while aretaining the 5-hy- ,droxy radical attached to the ll-carbon atom,

' have not been satisfactory due to the comparatively high susceptibility of the 11(5) -hydroxy- 40;;grouping to oxidation. Anomalously, it has not 12109511 possible to protect the 11(5) -hydroxy group by acylation while leaving the 3 and/or 20- hydroxy radicals free to be oxidized, since the 11(5) -hydroxyl group is subject to very pronounced steric hindrance and has resisted acylation by all methodsitried (see page 408 of the text Natural Products Related to Phenanthrene by Fieser andFieser, 3d edition, Rheinhold Publish-q ing Corp, New york, New York, 1949).

We have now discovered that A -3,20-diketo- 11(5) ,17(a) ,21 trihydroxy pregnene or its 21- acyl derivatives can be prepared, starting with A 3,11 diketo -'2l) cyanoi- 21 hydroxypregnene, or its 21-acy1 derivatives, by a novel procedure which is conducted as follows: A -3,11- diketo-ZO-cyano-Zlhydrozcy-ipregnene, or a 21- acyl derivative thereof (Compound 1 hereinbelow) is reacted with a ketonereagent, such as hydroxylamine, semicarbazide, arylhydrazines,

alkyl orthoformates, and the like, whereby the keto radical in the 3-position is replaced by an azomethine radical or by a dialkyl ketal grouping. The resulting A -3- (oximino, semicarbazido or arylhydrazino) -1l-keto-20-cyano-21- (hydroxy or acyloxy)-pregnene (Compound 2) or A 3,3 dialkoxy l1 keto 20 cyano 21- (hydroxy or acy1oxy)-pregnene (Compound 3) is then reacted with an alkali metal borohydride whereby the keto grouping attached to the 11- carbon atom of these compounds is converted to an 11( 3) -hydroxy substituent without substantially afiecting the unsaturated carbon nitrogen linkages in the ZO-cyano substituent, and without affecting the azomethine or ketal grouping in the 3-position of the molecule, thereby producing A -3-(oximino, semicarbazido or arylhydrazino) 11(5) hydroxy 20 cyano 21 (hydroxy or acyloxy) -pregnene (Compound 4) or A 3,3 dialkoxy 11(5) hydroxy 20 cyano 21- (hydroxy or acy1oxy)-pregnene (Compound 5) The resulting A -11(5) -hydroxy-20-cyano-21- (hydroxy or acy1oxy pregnene compound containing an azomethine or ketal grouping in the 3-position is reacted with a hydro1yzing agent, whereby the azomethine radical or ketal grouping is converted to a ketone thereby forming A 3 keto 11(13) hydroxy 20 cyano 21- (hydroxy or acyloxy)-pregnene (Compound 6). When the compound thus obtained is the A -3- keto-ll (p) ,21-dihydroxy-20-cyano-pregnene, it is converted, by reaction with a lower aliphatic carboxylic acid anhydride, to the corresponding 2l-acy1 derivative, A -3-keto-11(B)-hydroxy-20- cyano-21-acyloxy-pregnene. The resulting A -3- keto 11(5) hydroxy 20 cyano 21 acyloxypregnene is then reacted with osmium tetroxide thereby producing the 17,20-osmate ester of 3 keto 11(fi),17(a),20 trihydroxy 20 cyano- ZI-acyloxy-pregnene (Compound '7) which is then reacted with a hydrolyzing agent to form 3,20-diketo 11(fi),17(a) dihydroxy 21 acyloxypregnane (Compound 8). The latter compound is then reacted with bromine to form 3,20-diketo- 4 bromo l1(;3),17(a) dihydroxy 21 acyloxy-pregnane (Compound 9) which is reacted with a dehydrohalogenating agent to form A 320 diketo l1(;8),17(a) dihydroxy 21 acyloxy-pregnene (Compound 10). This compound is reacted with a hydrolyzing agent to produce A 3,20 diketo 11(fi),17(a) ,21 trihydroxypregnene, also known as Compound F (Compound 11). The reactions indicated hereinabove may be chemically represented as follows:

CHzOR CHrOR CHzOR l-ON (fl-0N (:JCN

HzQ 1 )sCH 4- --0 R10 H H RIO Compound 2 Oompmmd 1 Compound 3 Alkali Alkali t 1 lmetal borohydrlde l borohy d Ho )5 n (1) Hydrolyzing agent 2) Acylat ng Q agent 0 Compound 4 Osmium l tetrodde Compound 7 OHzOR l-ON C H103: (S-ON (1) Hydrolyzing agent (2) Acylating agent H Compound 6 Compound 6 O H: O R: t=o

Compound 8 anaemia Broniine QHzOBa. 'CHaORa I on on Dehydrqliaiovgenatmg Hydrolyzing agent agent Compound 9 .Compound 10 wherein R is hydrogen or an acyl radicaljfiais an :alkyl 'radicaL'RZ is an acyl radical, and Qis an :oximino, semicarbaz'ido or arylhydrazinoradical.

"In carrying out our novel process, A -3A1- ,diketo-"20-eyano-zl hydroxy pregnene, or .a 121- acyl derivative thereof .such as A +3,'l'1-diketo- 20-cyano-2l-acetoxy1pregnene, ,A' -i3,.l1-dike1to 20-cyano-2'1 prop'ionoxy -.pregnene, A -3,'1ldiketo-ZO-cyano 21 benzoxy-pregnene, and the like, is reacted with a ketone reagent, such as hydroxylamine, semicarbazide, an arylhydrazine, an alkyl orthoformate, and the like, to produce the corresponding A -.11-keto-20-cyano-'21-(hydroxy or acyfloxy)jpregnene containing in the B -position an azomethine or.ketal radical. Where the keto reagent used is hydroxylamine, semicarbazide or arylhydrazine, the compound obtainedcanbe represented by the formula:

onion -O.N

wherein .R. is hydrogen -or :acyl, and -,Q is .an oximino, .semicarbazido, or arylhydrazinoeradical. Wherethe ketone reagent utilized is an alkyl .orthoformate, .such. as ethyl 'orthoform-ate, methyl .orthoformate andthelike, there-is ob- .taineda compound of the formula:

onion G- ON Compound 11 bringing togetherin the reaction mixture a salt of the ketone reagent, such as hydroxylamine hydrochloride, semicarbazide hydrochloride, and the like, and an alkalinezmaterial such as sodium acetate, pyridine, and the like. The mixture of A -3,1l-diketo-ZO-cyano-Zl (hydroxy or acyloxy)-pregnene, ketone reagent, and solvent is ordinarily heated, preferably at a temperature of about C., for a periodof'two to three hours, thereby forming the A 3-(oximino, .serhicarbazido or arylhydrazino) ll keto 2mcyano'e2l- (hydroxy or acyloxy) -preg'nene. "'Iiliisproductis conveniently recovered by evaporating the reaction mixture to'a small volume, and diluting the solution with water, whereupon the desired product crystallizes and can be'recover'e'd by lfiltraltion.

The reaction involving an alkyl orthoiormate and A -3,11=diketo-20-cyano -.2l'-"(hydroxy .or acyloxy)-pregnene, is conveniently :carried out by bringing the reactants "together in the presence of a substantially anhydrous solvent, asfor example, benzene in the presence of .a mineral acid. We ordinarily conduct the? reaction employ'ing .ethyl 'orthoform'ate ,in solution in benzene containing absolute ethyl alcohol and a small amount of sulfuric acid. 'Itiisg preferred to employ atemperature of approximately 70 C. .under which conditions the reaction .is substantially complete in approximately'two hours. The ketal thus ,produced is conveniently recovered "from the -reaction isolu'tionfby first "shaking' the solution with an aqueous alkaline solution 'to'neutralize the acidic catalyst, followed "by evaporation of the organic layer Where'by'the desired A -3,3-dia1koxy-*1'1-keto=20 cyano -2l- (hydroxy or a'cyloxy) 'pregnene is obtained in the form of .an amorphous solid.

'The .A "-11-keto-2'0-cyano- 2l-K'hydroxy or acyloxyl-pregnene compound.containing in the 3- position, an 'azomethine or 'ketal substituent, "is then reacted with an alkali "metal borohydride, such as lithium iborohydride, sodiumborohydride, andthe like,whereby the'keto-substituent'in the Il -position is converted to an 11'( -B)-hydroxyl radical without substantially 'a'nect-i-ng the unsaturated carbon-nitrogen linkages in "the cyano radical attached to the 20-carbonatom, "and without substantially affecting the azome'thine lithium aluminum hydride,- -reduce -cyano radica'ils and 'azomethine; groupings to'the correspond- "The compound: thus -producediis containing in the 3-position an azomethine or ketal grouping. These compounds may be chemically represented as follows:

CHaOR -CN I and CHiOR E QN l wherein R, R1 and Q have the significance hereinabove defined.

The reaction between the A -11-keto-20- cyano-2l-(hydroxy. or acyloxy)-pregnene compound and the alkali metal borohydride is ordinarily carried out by bringing the reactants into intimate contact in the presence of a diluent, preferably in the presence of a solvent such as tetrahydrofuran, dimethylformamide, diethyl ether, and the like. It is ordinarily preferred to carry out the reaction by adding a tetrahydrofuran solution of the A -11-keto-20-cyano-2l- (hydroxy or acyloxy) pregnene compound to a solution of the alkali metal borohydride in tetrahydrofuran. This addition of the ll-keto compound to the reducing agent is preferably conducted portionwise, while maintaining the temperature of the reaction mixture at approximately 25 C. However, with the more active alkali metal borohydride (e. g. lithium borohydride), the reaction can be carried out at a lower temperature with lengthening of the reaction time. Conversely, with the less active sodium borohydride, a higher temperature may be necessary, it ordinarily being preferred to conduct the reaction, when using sodium borohydride as the reducing agent, at a temperature of about 60-70" 0. Thus, although it is ordinarily preferred to maintain the reaction temperature at about 25 C., it may be preferred to employ somewhat lower temperatures down to 0 C., when using lithium borohydride, as well as higher temperatures up to 70 C., when using sodium borohydride. When the reaction is carried out using lithium borohydride at a temperature of about 25 0., the reaction is ordinarily substantially complete in less than approximately one hour. When the reaction is carried out using sodium borohydride at the preferred temperature for this reducing agent of about 65 0., the reaction is substantially complete in less than 24 hours.

The resulting A -11(5) -hydroxy-20-cyano-21- (hydroxy or acyloxy)-pregnene compound containing in the 3-position an azomethine or ketal grouping is recovered from the reaction mixture by conventional means. This is ordinarily accomplished by cautiously acidifying the reaction mixture, preferably utilizing aqueous acetic acid, thereby decomposing excess alkalimetal borohydride. The A -11(3)-hydroxy-20-cyano-2l-(hydroxy or acyloxy)-pregnene compound can then be recovered by evaporating the reaction mixture to a small volume, preferably in vacuo, and diluting the concentrate with water. The product which separates, frequently in the form of an oil, can then be extracted from this aqueous mixture utilizing conventional water-immiscible solvents such as benzene, ether, chloroform, ethyl acetate and the like. The extract of A -11(3) -hydroxy- 20-cyano-2l-(hydroxy or acyloxy)-pregnene compound is then purified by conventional means, as for example, by washing successively with water and dilute aqueous alkaline solution, followed by drying. The product is recovered from the extract by evaporating the solvent therefrom, and can be further purified by recrystallization from solvents such as aqueous acetone, benzene, and the like. Where recrystallization from an organic solvent alone is insuiiicient to accomplish purification, it has been found convenient to subject the extract to a preliminary chromotographic fractionation utilizing activated alumina as the adsorbent.

The 11 -11 s) -hydroxy-20-cyano-21-(hydroxy or acyloxy)-pregnene compound containing in the 3-position an azomethine or ketal grouping is then reacted with an acidic hydrolyzingagent, thereby producing A 3 keto 11(5) ,21 dihydroxy-20-cyano-pregnene or a 21-acyl derivative thereof such as A"3-keto-l1(fi)-hydroxy-20- cyano 21 acetoxy pregnene, A" 3 keto- 11(5) hydroxy 20 cyano 21 propionoxy pregnene, A 3 keto 11(5) hydroxy 20- cyano-2l-benzoxy-pregnene, and the like. In the case of A -11(5)-hydroxy-20-cyano-21-(hydroxy or acyloxy) -pregnene compounds containing a 3-azomethine substituent, it is common to conduct the hydrolysis under acid conditions in the presence of a carbonyl acceptor, as for example, pyruvic acid, benzoyl formic acid, and the like. The hydrolysis reaction is conveniently carried out by heating the mixture of reactants at an elevated temperature of about C. under which conditions the hydroylsis reaction is ordinarily substantially complete in approximately 4 hours. In the case of A -11(fi) hydroxy 20 cyano 21 (hydroxy or acyloxy) pregnene compounds containing a 3-ketal grouping, the reaction is conveniently carried out by allowing the pregnene compound to stand in solution in the presence of a mineral acid, such as aqueous hydrochloric acid, aqueous sulfuric acid, and the like, at a temperature of approximately 25 C. for a period of about 15-20 hours. The A 3 keto 11(5) hydroxy 20 cyano 21- (hydroxy or acyloxy) -pregnene obtained by either of the foregoing hydrolysis procedures, is recovered from the hydrolysis mixture by conventional means as, for example, by evaporating said mixture in vacuo and extracting the concentrate containing A" 3 keto 11(5) hydroxy- 20 cyano 21 (hydroxy or acyloxy) -pregnene with a solvent such as ethyl acetate.

Although either A 3 keto 11(fi),21 dihydroxy-20-cyano-pregnene or its 21-acyl derivative can be used in the subsequent reaction with osmium tetroxide, it is ordinarily preferred to utilize the A -3-keto-11o8) -hydroxy-20-cyano- 21-acyloxy-pregnene in this reaction. The A 3 keto 11(fl),21 dihydroxy 20 cyanopregnene is preferably converted to its 21- acyl derivative by reaction with an acylating agent. It is ordinarily preferred to utilize, as the acylating agent for this reaction, a lower aliaccaee above, was dissolved in 300 ml. of dry tetrahydrofuran (dried over metallic sodium) and this solution was added, dropwise, with agitation over a hour period, to a solution of 9.7 g. of lithium borohydride in 300 ml. of dry tetrahydrofuran, while maintaining the temperature of the mixture at approximately 25 C. The resulting mixture was stirred for an additional period of 20 minutes at a temperature of 25 C., and was then cooled and stirred for minutes at about 5 C. Six hundred milliliters of aqueous acetic acid containing 120 ml. of glacial acetic acid was added cautiously, with stirring, to the resulting mixture whereupon a vigorous evolution of gas occurred. The resulting mixture was evaporated in vacuo to a volume of approximately 600 ml., and the concentrated solution was then diluted with approximately 600 ml. of water. The oily organic layer which separated was extracted from the mixture utilizing 600 ml. of a 5:1 benzeneether mixture followed by two 200 ml. portions of benzene. The combined benzene-ether extracts were washed with two 200 ml. portions of water, one 200 ml. portion of 5% aqueous sodium bicarbonate solution, and one 200 ml. portion of saturated aqueous sodium chloride solution. The washed benzene-ether extract was then dried over 30 g. of anhydrous magnesium sulfate, the dry solution was filtered, and the solvents were evaporated therefrom in vacuo to give 40.1 g. of crude A 3,3 -diethoxy-11(fi),21-dihydroxy-20- cyano-pregnene which was obtianed in the form of a fiufiy, pale-yellow, amorphous solid.

Example 3 40.1 g. of crude A "-3,3-diethoxy11(c),21-dihydroxy cyano pregnene, prepared as described hereinabove, was dissolved in a mixture of 425 ml. of acetone and 55 ml. of water. To this solution was added 4.0 ml. of 2.5 N aqueous hydrochloric acid, and the resulting solution was allowed to stand at room temperature for a period of about 30 hours. ml. of 5% aqueous sodium bicarbonate solution was then added to the reaction mixture, and the resulting solution was evaporated in vacuo to a small volume, thereby evaporating substantially all of the acetone present in the solution; during this evaporation, a pale-yellow oil separated. The residual material was diluted with 800 ml. of water, and the oily organic material was extracted from the aqueous mixture utilizing one 400 ml. portion and two 300 ml. portions of chloroform. The combined chloroform extracts were washed successively with one 300 ml. portion of 5% aqueous sodium bicarbonate solution and one 300 ml. portion of water, and the washed chloroform extracts were then dried over 15 g. of anhydrous magnesium sulfate. The dry chloroform was filtered and the chloroform evaporated in vacuo to give 38.8 g. of crude A -3keto11(fl),2l-dihydroxy-20- cyano-pregnene which was obtained in the form of a pale, buff-colored, partly crystalline solid. This crude material, after one recrystallization from aqueous acetone, gave 15.3 g. of substantially pure A -3-ketone-1l08),2l-dihydroxy-20- cyano-pregnene which was obtained in the form of colorless needles; M. 1?. 2165-2185 C. (melted partly at 206 C., then resolidified). An analytically pure sample obtained by several recrystallizations from aqueous acetone melted at 217.5- 221.5 C. (melted partly at 207-210 C., then solidified); M3 -=+24.4 (1.03 in acetone) 12 Analysis.Calcd. for C22H3103NZ c, 73.91; H. 8.74. Found: c, 74.12; H, 8.73.

Example 4 2.32 g. of A -3,3-diethoxy-ll-keto-ZO-cyano- 21-hydroxy-pregnene was dissolved in 20 ml. of tetrahydrofuran, and to this solution was added a solution of 0.84 g. of sodium borohydride in 10 ml. of tetrahydrofuran, 10 ml. of water and 0.2 ml. of 2.5 N aqueous sodium hydroxide. The mixture was heated under reflux for a period of approximately 20 hours. The reaction mixture was then cooled to room temperature, and 35 ml. of 10% aqueous acetic acid was added to the cooled mixture thereby decomposing excess sodium borohydride.

The resulting clear, colorless solution was evaporated in vacuo to a volume of about 40-50 ml., and the pale-yellow oil which separated was extracted with three 50 ml. portions of ethyl acetate. The ethyl acetate extracts were combined and the resulting ethyl acetate solution was washed successively with two 50 ml. portions of water, with two 50 ml. portions of 5% aqueous sodium bicarbonate solution, with one 50 ml. portion of water, and with one 50 ml. portion of saturated aqueous sodium chloride solution. The washed ethyl acetate solution was dried over 5 g. of anhydrous magnesium sulfate, the solution was filtered, and the solvent was evaporated therefrom in vacuo to give 1.985 g. of A -3,3- diethoxy- 1 1 (B) ,21 -dihydroxy-ZO-cyano-pregnene which was obtained in the form of a pale-bulicolored, amorphous solid.

This material was dissolved in 25 m1. of acetone, and to this solution was added 5 ml. of water and 0.2 ml. of 2.5 N aqueous hydrochloric ac1d. This solution was allowed to stand at room temperature for a period of approximately 20 hours, 5.0 ml. of 5% aqueous sodium bicarbonate solution and 20 ml. of water were added thereto, and the resulting solution was evaporated in vacuo to a small volume, thereby removing the major portion of the acetone. The buif-colored oil which separated was extracted with one 50 ml. portion and two 30 ml. portions of ethyl acetate. The ethyl acetate extracts were combined and the ethyl acetate solution was washed successively with two 40 ml. portions of water, with one 40 ml. portion of 5% aqueous sodium bicarbonate solution, with one 40 ml. portion of water, and with one 40 ml. portion of saturated aqueous sodium chloride solution. The washed ethyl acetate solution was dried over 5 g. of anhydrous magnesium sulfate, the solution was filtered, and the ethyl acetate was evaporated therefrom in vacuo to give a partly crystalline pale, buff-colored residue weighing 1.705 g. This material was recrystallized from acetone to give 0.73 g. of substantially pure A -3-keto11(,8),21- dihydroxy 20 cyano pregnene which was obtained in the form of rosettes of heavy colorless needles; M. P. 215-218 C. with softening at 213 C. (partly melted at 203-206 C., then resolidified); no depression in melting point was observed when this material was mixed with A"- 3-keto-11(,B),21-dihydroxy-20 cyano-pregnene prepared as described in Example 3.

Example 5 hydrochloride and 12.55 g. of anhydrous sodium acetate dissolved in 28mlc t waterand 28 ml. oi glacial aceticacid; the latter solution: was rinsed into the reaction mixture with an additional 44 ml. of glacial acetic'acid. The resulting mixture was heated toa temperature of 65-70? C. for a period of approximately 2 hours during which time a small amount of crystalline material separatech- The"resulting suspension was evaporated in vacuo t0-athick slurry of crystalline solid, and 200 m1 ofwater was added to said slurry. The resulting aqueous mixturewas agitated vigorously to suspend cakedmaterial, the slurry was then filtered and the crystalline product washed twice with water to give 24.2 g. of colorless needles which melted at 225- 230 C. with evolutionoi gas. One recrystallizationofthis productfror'n methanol-chloroform aftorded 20.2 g. of substantially pure A -3- semicarbazidb-ll-lgeto-ZO cyano 2i hydroxypregnene; M. P. 238-240 C. (vigorous evolution of gas). This product was further purified by repeated recrystallization from methanol-chloroform and the product dried at 140 C. to give analytically pure A -3-semicarbazid'o-1l-keto- 2'0-cyano-2l-hydroxy-pregnene; M. P. 244-245" C. (evoluton of gas Ana-Zysis .C'alcd tor Found: N, 13.47.

12.36 g. of A semicarbazido-l'l keto 20- cyano-2l-hydroxy-pregnene (M. P. 238- -240 C.) was dissolved in 1500 ml. of dry tetrahydrofuran (dried over inetallicsodium), and this solution was added, with stirring, over a period of approximately /2 hour, to a solution of 4.36 g. of lithiuniborohydride in 200ml. of dry tetrahy drofuran, while maintaining the temperature of the mixture at approximately 25 C. The resulting mixture was stirred for an additional period of 20 minutes at a temperature of 25" C., and was then cooled and stirred for 10 minutes at about 5 C. Four hundred and fifty milliliters of aqueous acetic acid containing 51.5 ml. of glacial acetic acid was added cautiously, with stirring, to the resulting mixture, and the clear, colorless reaction mixture was-evaporated in vaeuo under a nitrogen: atmosphere to a volume of approximately 400ml. The colorless oily organic material which separated was extracted from the mixture-utilizingone 350 ml. portion of chloroform and two 150 ml.- portions of chloroform. The combined chloroform extracts were washed with two 250 ml. portions of water, and with one 200 ml. portion of 5% aqueous sodium bicarbonate solution, and the washed chloroform extracts were dried over g. of anhydrous sodium sulfate. The dry chloroform solution was then filtered and the chloroform evaporated to give 11.5 g. of crude A -3- semicarbazido-11('B),21 dihydroxy 20 cyanopregne'ne which was obtained in the form of a gummy, buff-colored solid.-

4.5 grams of this material was mixed with 15 ml. of glacial acetic acid, 7.5 ml. of water, 9.05

g. of anhydrous sodium acetateand 9.0 m1. of 90% pyruvic acid, and'the mixture was heated at a temperature of 80 C. ariatmosphere of nitrogen for a period of about 3 hours. The reaction mixture was cooled to room temperature, an additional 0.9 ml. of 90% pyruvic acid was added thereto, and the resulting mixture was heated under nitrogen at a temperature of 80 C. for an additional one-hour period. The resulting mixture was allowed to stand overnight at room temperature whereupon agon 14 siderable quantity of crystalline material; 'sepae ratedi One hundredand: eightymilliliters. of water was added to this mixture, and the or-- ganic material was; extractedtherefrom utilizing oneml.- portion andt'hree 35 ml. portions of chloroform. The combined chloroform extractswere washed with--two-5-0 ml. portions of water, two 50 ml. portions of 5%. aqueous sodium bicarbonate solution, again with '50 ml. or water, andthe washed chloroform solution was then dried over 5' g. of anhydrous magnesium su-lfate.- The dry chlorotorm' solution was then filtered and the solvent was evaporated-from the filtrate in vacuo to give 4.25 g. of partly crystalline, light, bufieolored materials This product, after one-recrystallization from acetone, afforded 1.15 g-.; ofsubstantially pure A -3-keto- 1198-),21-dihydroxy 20-- cyanopregnene; which was obtained in the form of colorless needles; M. P.- 216.5-219.5 C. (melted partly at 206.5 to 20s 0., their resolidified); there was no' depression in-melting point when this material was admixed with A -3-keto-1 1(p),21-dihydroxy-20-cyano-pregnene= as prepared. via the 3-diethyl ketal as described in Example 3 hereinabove.

Efidfiibld Five grams of A -3-kto- 1H'B) ,21-dili'yd'ro'xyz-o-c ano-pregnene was warmed ge'ntly' withioo' m1. ofacetic anhydride until the material hadcompletely dissolved. Eight'milliliters of pyridine was added to the so1utio'n, arld'tlirsfiltin'g" mixture was heated at a temperature of 65 c. for a period or apprcximat-eiy 'h-ouri; The reaction mixture was cooled to tern: perature, 20ml. of waterwasadueameretowith external cooling, andtiie'mixture was-"vigorously agitated to decompose the excess acetic" anhydride. The mixture thus obtained was d1- luted to a volume of 500 ml. with water, and the resulting suspension of crystalline material was stirred at appr'oxiniatelyfroom temperature for a period of about 1 hour; the resulting suspension' was then cooledrt'o about" 0 C; and. stirred, for about two hours' 'at that temperature. The slurry was filtered and the crystalline product was washed with rou'rcsmi portions or-"wat'er, and dried at 60 C. overnight to give approxi' mately 5.27 g. of substantially pure A -3-keto- 11(5) -hydroxy-20-cyano-21 acetoxy pregnene which was obtained'iii "thelfo'rm of'colorle'ss needles; M. P. 169-171 C. This material was repeatedly recrystallized" from acetone-ether to give colorless" needles of analytically pure A -3 kerb-11(5) -hydroxy;20 cyafio-2I acetoxy-pregnene; M. 1?. 17047115 c..;" [aJ -=+3'2.4' (1.02, acetone) line material separated and could be recovered by filtration, if desired-, and dried to give the -1 '7- ZO- smate ester of 3 keto 11(B).,1':7 (-d).-,20F- 'tri.

hydroxy cyano 21 acetoxy pregnane.) The final reaction mixture was diluted with 'ml. of chloroform and 0.30 g. of filtercel was added to the mixture. One milliliter of concentrated aqueous hydrochloric acid was then added dropwise with stirring to the resulting suspension, and the suspension was stirred for a period of approximately four hours. The solid material was removed by filtration and washed thoroughly with hot chloroform. The filtered chloroform solution was washed once by shaking with water, and was then stirred vigorously for a period of about one hour with a solution containing 1.1 g. of potassium carbonate dissolved in 21 ml. of water. The chloroform layer was separated, washed once with 15 ml. water, dried over 4 g. of anhydrous sodium sulfate, and the dry chloroform solution filtered. The filtered chloroform solution was then evaporated in vacuo to a volume of approximately 5.5 1111.; this solution can be evaporated to dryness, if desired, to give 3,20-diketo-1l(fi) ,17 (a) dihydroxy-21-acetoxy-pregnane, contaminated with a small amount of 3,20 diketo 11(5) ,17(a) ,21 trihydroxy-pregnane.

To the concentrated solution (volume 5.5 ml.) was added 0.11 ml. of pyridine and 0.27 ml. of acetic anhydride. The resulting solution was heated at a temperature of approximately 60- 65 C. for a period of approximately one-half hour, and the reaction solution was cooled to approximately 0 C. 16 ml. of petroleum ether (B. P. 30-60 C.) was added to the cooled solution, whereupon crystalline material separated. The resulting slurry was filtered, and the crystalline material was washed twice with petroleum ether (B. P. 3060 C.) and dried to give approximately 0.35 g. of substantially pure 3,20-diket-o- 11(5) ,1701) -dihydroxy 21 acetoxy pregnene. This material was further purified by repeated recrystallization from acetone-petroleum ether (B. P. 30-60 C.) to give analytically pure 3,20- diketo 11(5) ,17(a) dihydroxy 21 acetoxypregnane which was obtained as colorless prisms; M. P. 217.6-219.8 C.; [a] '=+86.6 (1.05, acetone).

Analysis.Calcd. for 02311 .406: C, 67.95; H, 8.43. 7 Found: C, 68.20; H, 8.19.

Example 9 0.45 gram of A "-3-keto-11(,3) -hydroxy-20- cyano 21 acetoxy pregnene, prepared as described in Example 7 hereinabove, was dissolved in 4.5 ml. of benzene (thiophene-free) containing 0.3 ml. of pyridine, and 0.31 g. of osmium tetroxide was added to the solution. The mixture was agitated to bring the components into solution, and the resulting solution was allowed to stand at room temperature for a period of approximately forty-eight hours; (crystallization of the 17,20-osmate ester of 3-keto-11(,6),17(a),20-trihydroxy 20 cyano 21 acetoxy pregnane was noted after approximately six hours).

At the end of forty-eight hours, the reaction mixture was mixed with 21.2 cc. of water, 6.2 ml. of benzene, 14.7 ml. of methanol and an intimate mixture of 2.20 g. of potassium bicarbonate with 2.02 g. of sodium sulfite. The resulting mixture was stirred at room temperature for a period of approximately twenty hours, thereby hydrolyzing the osmate ester. The hydrolysis mixture was filtered to remove the precipitated osmium salts, and the filtered material was washed with four 25 ml. portions of hot chloroform. The filtrate and washings were combined, the layers were separated, and the aqueous phase was then evaporated in vacuo to approximately one-third its initial volume. The concentrated aqueous solution was extracted with seventeen 10ml. portions of chloroform, and the chloroform washings and extracts were combined and dried over 10 g. of anhydrous sodium sulfate. The dry chloroform solution was then filtered and evaporated to dryness to give 3,20-dik6l30-11(B),17(a)-dlhYdl'0XY- 2l-acetoxy-pregnane which was obtained as a crystalline solid; contaminated with a small amount of 3,20 diketo 11(5) ,17(a) ,21 trihydroxy-pregnane.

This material was dissolved in 5 ml. of acetic anhydride, 2 ml. of pyridine was added to the solution, and the resulting solution was heated at a temperature of 60-70 C. for a period of about thirty minutes. At the end of this time, the excess acetic anhydride was cautiously decomposed by adding 2.3 ml. of water to the acetylation mixture, with cooling. Thirty milliliters of water was then slowly added, with swirling, to the resulting solution, whereupon a precipitate formed. The resulting slurry was allowed to stand at a temperature of approximately 0 C. for about 1 hour, and the precipitated material was recovered by filtration. The filtered material was washed with five 10 ml. portions of water, and dried at a temperature of 60 C. to give 0.36 g. of substantially pure 3,20-diketo-1103) ,17(a)- dihydroxy-21-acetoxy-pregnane; M. P. 205-210 C.

This material was further purified by dissolving it in 15 cc. of hot acetone, treating the acetone solution for a period of 10-15 minutes with 0.08 g. of activated charcoal (Nuchar), and the resulting charcoal slurry was filtered through d-iatomaceous silica (Supercel). The filtered acetone solution was evaporated to a volume of 5 to 6 ml., and 70 ml. of petroleum ether (B. P. 30-60 C.) was carefully added to the concentrated acetone solution, whereupon a crystalline product separated. The slurry was allowed to stand for approximately one hour to complete crystallization, the crystalline material was recovered by filtration, washed with three 10 ml. portions of petroleum ether (B. P. 30-60" C.) and dried to give 0.29 g. of substantially'pure 3,20- diketo 11(13),17(a) dihydroxy 21 acetoxypregnane; M. P. 2142l5 C. No depression in melting point was observed when this compound was mixed with 3,20 diketo 11(5) ,17(a) -dihydroxy-2l-acetoxy-pregnane prepared as described in Example 8 hereinabove.

Example 10 One-half gram of 3,2U-diket0-11( 3),17(a)di hydroxy-2l-acetoxy-pregnane was dissolved in 10 ml. of glacial acetic acid containing 0.25 ml. of 1 N hydrogen bromide in acetic acid, and to this solution was added dropwise, with stirring, over a five-minute period, a mixture of 1.13 ml. of 2.05 N bromine in acetic acid and 1.12 ml. of 1 M sodium acetate in acetic acid. The resulting mixture was stirred for an additional period of approximately 15 minutes, at the end of which time 6 ml. of water was added, dropwise, to the reaction mixture, whereupon the solution became cloudy and crystalline material separated. The resulting slurry was cooled at about 0 C. for a period of approximately four and one-half hours, and the crystalline material was recovered by filtration and dried to give 0.20 g. of 3,20-diketo-4-bromo-ll (d) ,17 (a) -dihydroxy- 21-acetoxy-pregnane which was obtained in the 17 form of colorless needles; M. P. 186-18? C., dec. A substantially pure sample of 3,20-diketo-4- bromo-11(,B),17(a) dihydroxy 21 acetoxypregnane, prepared substantially as described above, melted at 190.4-191.6 C. (dec.); [a] -=+99 (1.0 acetone).

Example 11 0.104 gram of semicarbazide hydrochloride and 0.114 g. of anhydrous sodium acetate were dissolved in 22.5 ml. of glacial acetic acid containing 0.5 ml. of water, and this solution was added to a solution containing 0.15 g. of 3,20- diketo-i-bromo 11(B).,17(a) dihydroxy 21- acetoxy-pregnane dissolved in 7.5 ml. of glacial acetic acid. The resulting mixture was heated at a temperature of about 65-75" C. in an atmosphere of nitrogen for a period of approximately two hours. The reaction mixture was cooled to room temperature, and 1.43 g. of anhydrous sodium acetate and 1.4 ml. of 90% aqueous pyruvic acid was added to the cooled mixture. The resulting mixture was then heated at a temperature of about 7072 C. in an atmosphere of nitrogen for a period of about four hours, and was then allowed to stand at room temperature for an additional 12 hour period. Sixty milliliters of water were added to the reaction mixture, and the resulting solution was evaporated in vacuo to a volume of about 5 ml. Twenty milliliters of water were added to the concentrated solution whereupon crystalline material separated which was recovered by filtration, washed thoroughly with water, and dried to give 0.70 g. of substantially pure A -3,20- diketo 11(}8),17(a) dihydroxy 21-acetoxypregnene which was obtained in the form of light, buff-colored microprisms; M. P. 208214 C. with slight previous softening. This mixture was further purified by a single recrystallization from ethyl acetate to give analytically pure A -3,20-diketo-11( 3),17(a)-dihydroxy 21- acetoxy pregnene which was obtained in the form of colorless prisms; M. P. 218.5-220.5 C. with slight previous softening (microblock);

the melting point of a mixture of this material with an authentic sample of 17(a) -hydroxycorticosterone acetate showed no depression; the identity of the material prepared as described above with said authentic sample was further confirmed by comparative infra-red spectra.

Various changes and modifications may be made in carrying out the present invention without departing from the spirit and scope thereof. Insofar as these changes and modifications are within the purview of the annexed claims, they are to be considered as part of our invention.

We claim:

1. A -ZO-cyano-pregnene compounds having a hydroxy substituent attached to the C11 carbon atom.

2. -A "-3,3-bis(lower alkoxy) -l1-hydroxy-20- cyano-21- (lower alkanoyloxy) -pregnene.

3. A -3,3-diethoxy 11(5) hydroxy-20-cyano-2l-acetoxy-pregnene.

4. A "-3,3-bis(lower alkoxy)-ll,21dihydroxy- ZO-cyanO-pregnene.

5. A -3-semicarbazido-11(,3) hydroxy 20- oyano-Zl-acetoxy-pregnene.

6. A -3-semicarbazido-11(B),21 dihydroxy- 20-cyano-pregnene.

'7. A "3keto ll hydroxy-20-cyano 21- (lower alkanoyloxy)-pregnene.

8. A -3-keto-11( 8)-hydroxy 20 cyano-Zlacetoxy-pregnene.

9. A "-3-keto-11(;3),21 dihydroxy-20-cyanopregnene.

ROBERT P. GRABER. NORMAN L. WENDLER.

References Cited in the file of this patent UNITED STATES PATENTS Number 

1. $17-20-CYANO-PREGNENE COMPOUNDS HAVING A HYDROXY SUBSTITUENT ATTACHED TO THE C-11 CARBON ATOM. 